WordPress at a glance
action is not described

woocommerce_cart_loaded_from_session action-hook . WC 1.0

Usage

add_action( 'woocommerce_cart_loaded_from_session', 'action_function_name_509' );
function action_function_name_509( $cart ){
	// action...
}
$cart
-

Where the hook is called

WC_Cart_Session::get_cart_from_session()
woocommerce_cart_loaded_from_session
woocommerce/includes/class-wc-cart-session.php 173
do_action( 'woocommerce_cart_loaded_from_session', $this->cart );

Where in WP core the hook is used WooCommerce

woocommerce/includes/class-wc-cart-session.php 51
add_action( 'woocommerce_cart_loaded_from_session', array( $this, 'set_session' ) );